Writing tool and dispensing unit thereof

Abstract

A writing tool includes a writing unit, a capillary member, a dispensing unit, and a replaceable ink cartridge. The capillary member, the dispensing unit, and the replaceable ink cartridge are mounted in the writing unit. The dispensing unit contacts the capillary member and has at least one cutting portion. The replaceable ink cartridge accommodates ink therein and has a film at one end thereof. The replaceable ink cartridge can be installed in the dispensing unit and the film can be pierced and cut by the at least one cutting portion. The ink flows through the film and is delivered to the writing unit via the capillary member and the dispensing unit for writing. The writing tool can thus dispense the ink fluently and leave no residual ink.

What is claimed is: 
     
       1. A writing tool, comprising:
 a writing unit having a tube and a nib mounted at an end of the tube; 
 a capillary member mounted in the tube and contacting the nib; 
 a dispensing unit mounted in the tube and having an inbound part having at least one cutting portion, a first coupling portion, and an external passage, the at least one cutting portion having at least one cutting edge formed on a top thereof, the first coupling portion surrounding the at least one cutting portion, the external passage being defined between the at least one cutting portion and the first coupling portion; 
 an outbound part contacting the capillary member; and a dispensing passage communicating with the outbound part, the inbound part, and the external passage; and a replaceable ink cartridge mounted in the tube and communicating with the dispensing unit, the replaceable ink cartridge having a second coupling portion connected with the first coupling portion; ink contained in the replaceable ink cartridge; and a film cut by the at least one cutting edge for output of the ink; 
 wherein the at least one cutting edge comprises at least one first end and at least one second end, and a height difference is defined between the at least one first end and the at least one second end; 
 wherein the dispensing unit comprises a second cutting portion, and wherein the second cutting portion and the at least one cutting portions are arranged annularly and and spaced at intervals about a dispensing passage. 
 
     
     
       2. The writing tool as claimed in  claim 1 , wherein the first coupling portion comprises an abutting edge annularly formed at an outer periphery thereof and defines an assembly stroke being an axial distance between the abutting edge and an uppermost side of the first coupling portion, the assembly stroke being larger than the height difference of the at least one cutting portion. 
     
     
       3. The writing tool as claimed in  claim 1 , wherein each said cutting edges of the at least one cutting portions is curved and inclined from the at least one first end to the at least one second end. 
     
     
       4. The writing tool as claimed in  claim 1 , wherein the dispensing passage comprises an internal passage surrounded by the cutting portions and communicating with the external passage via at least two guiding gaps. 
     
     
       5. The writing tool as claimed in  claim 1 , wherein the at least one cutting edge is curved and inclined from the at least one first end to the at least one second end. 
     
     
       6. The writing tool as claimed in  claim 1 , wherein the dispensing passage comprises an internal passage surrounded by the at least one cutting portion and communicating with the external passage via at least one guiding gap. 
     
     
       7. The writing tool as claimed in  claim 1 , wherein the first coupling portion of the inbound part comprises at least one sealing rib, an outer diameter of the at least one sealing rib being not smaller than an inner diameter of the second coupling portion. 
     
     
       8. The writing tool as claimed in  claim 1  further comprising a cap sleeved onto the replaceable ink cartridge for rotatably driving and enabling the replaceable ink cartridge to be installed into the tube. 
     
     
       9. The writing tool as claimed in  claim 8 , wherein
 the cap comprises a plurality of push lugs formed annularly at a lowermost side thereof and spaced at intervals; 
 the second coupling portion comprises a plurality of abutting ribs formed annularly at an outer periphery of the replaceable ink cartridge and spaced at intervals; and 
 the cap rotatably drives the replaceable ink cartridge into the tube in such a way that the push lugs are pushed against the abutting ribs, respectively. 
 
     
     
       10. A dispensing unit of a writing tool, the writing tool having a capillary member, a tube, and a replaceable ink cartridge, the dispensing unit being mounted in the tube and comprising:
 an outbound part contacting the capillary member; 
 an inbound part having at least one cutting portion having at least one cutting edge formed on a top thereof; 
 a first coupling portion surrounding the at least one cutting portion; and 
 an external passage defined between the at least one cutting portion and the first coupling portion; and 
 a dispensing passage communicating with the outbound part, the inbound part, and the external passage; 
 wherein the at least one cutting edge comprises at least one first end and at least one second end, and a height difference is defined between the at least one first end and the at least one second end; 
 wherein the dispensing unit comprises a second cutting portion, and wherein the second cutting portion and the at least one cutting portion are arranged annularly and spaced at intervals about a dispensing passage. 
 
     
     
       11. The dispensing unit of the writing tool as claimed in  claim 10 , wherein the first coupling portion comprises an abutting edge annularly formed at an outer periphery thereof and defines an assembly stroke being an axial distance between the abutting edge and an uppermost side of the first coupling portion, the assembly stroke being larger than the height difference of the at least one cutting portion. 
     
     
       12. The dispensing unit of the writing tool as claimed in  claim 10 , wherein each said cutting edges of the at least one cutting portions is curved and inclined from the at least one first end to the at least one second end. 
     
     
       13. The dispensing unit of the writing tool as claimed in  claim 10 , wherein the dispensing passage comprises an internal passage surrounded by the cutting portions, and the internal passage communicates with the external passage via at least two guiding gaps. 
     
     
       14. The dispensing unit of the writing tool as claimed in  claim 10 , wherein the at least one cutting edge is curved and inclined from the at least one first end to the at least one second end. 
     
     
       15. The dispensing unit of the writing tool as claimed in  claim 10 , wherein the dispensing passage comprises an internal passage surrounded by the at least one cutting portion, and the internal passage communicates with the external passage by at least one guiding gap. 
     
     
       16. The dispensing unit of the writing tool as claimed in  claim 10 , wherein the replaceable ink cartridge comprises a second coupling portion sleeved onto the first coupling portion of the inbound part, the first coupling portion comprises at least one sealing rib, and an outer diameter of the at least one sealing rib is not smaller than an inner diameter of the second coupling portion.